// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

// Glue code between CodeMirror and Tern.
//
// Create a CodeMirror.TernServer to wrap an actual Tern server,
// register open documents (CodeMirror.Doc instances) with it, and
// call its methods to activate the assisting functions that Tern
// provides.
//
// Options supported (all optional):
// * defs: An array of JSON definition data structures.
// * plugins: An object mapping plugin names to configuration
//   options.
// * getFile: A function(name, c) that can be used to access files in
//   the project that haven't been loaded yet. Simply do c(null) to
//   indicate that a file is not available.
// * fileFilter: A function(value, docName, doc) that will be applied
//   to documents before passing them on to Tern.
// * switchToDoc: A function(name, doc) that should, when providing a
//   multi-file view, switch the view or focus to the named file.
// * showError: A function(editor, message) that can be used to
//   override the way errors are displayed.
// * completionTip: Customize the content in tooltips for completions.
//   Is passed a single argument—the completion's data as returned by
//   Tern—and may return a string, DOM node, or null to indicate that
//   no tip should be shown. By default the docstring is shown.
// * typeTip: Like completionTip, but for the tooltips shown for type
//   queries.
// * responseFilter: A function(doc, query, request, error, data) that
//   will be applied to the Tern responses before treating them
//
//
// It is possible to run the Tern server in a web worker by specifying
// these additional options:
// * useWorker: Set to true to enable web worker mode. You'll probably
//   want to feature detect the actual value you use here, for example
//   !!window.Worker.
// * workerScript: The main script of the worker. Point this to
//   wherever you are hosting worker.js from this directory.
// * workerDeps: An array of paths pointing (relative to workerScript)
//   to the Acorn and Tern libraries and any Tern plugins you want to
//   load. Or, if you minified those into a single script and included
//   them in the workerScript, simply leave this undefined.

(function(mod) {
  if (typeof exports == "object" && typeof module == "object") // CommonJS
	mod(require("../../lib/codemirror"));
  else if (typeof define == "function" && define.amd) // AMD
	define(["../../lib/codemirror"], mod);
  else // Plain browser env
	mod(CodeMirror);
})(function(CodeMirror) {
  "use strict";
  // declare global: tern

  CodeMirror.TernServer = function(options) {
	var self = this;
	this.options = options || {};
	var plugins = this.options.plugins || (this.options.plugins = {});
	if (!plugins.doc_comment) plugins.doc_comment = true;
	if (this.options.useWorker) {
	  this.server = new WorkerServer(this);
	} else {
	  this.server = new tern.Server({
		getFile: function(name, c) { return getFile(self, name, c); },
		async: true,
		defs: this.options.defs || [],
		plugins: plugins
	  });
	}
	this.docs = Object.create(null);
	this.trackChange = function(doc, change) { trackChange(self, doc, change); };

	this.cachedArgHints = null;
	this.activeArgHints = null;
	this.jumpStack = [];

	this.getHint = function(cm, c) { return hint(self, cm, c); };
	this.getHint.async = true;
  };

  CodeMirror.TernServer.prototype = {
	addDoc: function(name, doc) {
	  var data = {doc: doc, name: name, changed: null};
	  this.server.addFile(name, docValue(this, data));
	  CodeMirror.on(doc, "change", this.trackChange);
	  return this.docs[name] = data;
	},

	delDoc: function(id) {
	  var found = resolveDoc(this, id);
	  if (!found) return;
	  CodeMirror.off(found.doc, "change", this.trackChange);
	  delete this.docs[found.name];
	  this.server.delFile(found.name);
	},

	hideDoc: function(id) {
	  closeArgHints(this);
	  var found = resolveDoc(this, id);
	  if (found && found.changed) sendDoc(this, found);
	},

	complete: function(cm) {
	  cm.showHint({hint: this.getHint});
	},

	showType: function(cm, pos, c) { showContextInfo(this, cm, pos, "type", c); },

	showDocs: function(cm, pos, c) { showContextInfo(this, cm, pos, "documentation", c); },

	updateArgHints: function(cm) { updateArgHints(this, cm); },

	jumpToDef: function(cm) { jumpToDef(this, cm); },

	jumpBack: function(cm) { jumpBack(this, cm); },

	rename: function(cm) { rename(this, cm); },

	selectName: function(cm) { selectName(this, cm); },

	request: function (cm, query, c, pos) {
	  var self = this;
	  var doc = findDoc(this, cm.getDoc());
	  var request = buildRequest(this, doc, query, pos);

	  this.server.request(request, function (error, data) {
		if (!error && self.options.responseFilter)
		  data = self.options.responseFilter(doc, query, request, error, data);
		c(error, data);
	  });
	},

	destroy: function () {
	  if (this.worker) {
		this.worker.terminate();
		this.worker = null;
	  }
	}
  };

  var Pos = CodeMirror.Pos;
  var cls = "CodeMirror-Tern-";
  var bigDoc = 250;

  function getFile(ts, name, c) {
	var buf = ts.docs[name];
	if (buf)
	  c(docValue(ts, buf));
	else if (ts.options.getFile)
	  ts.options.getFile(name, c);
	else
	  c(null);
  }

  function findDoc(ts, doc, name) {
	for (var n in ts.docs) {
	  var cur = ts.docs[n];
	  if (cur.doc == doc) return cur;
	}
	if (!name) for (var i = 0;; ++i) {
	  n = "[doc" + (i || "") + "]";
	  if (!ts.docs[n]) { name = n; break; }
	}
	return ts.addDoc(name, doc);
  }

  function resolveDoc(ts, id) {
	if (typeof id == "string") return ts.docs[id];
	if (id instanceof CodeMirror) id = id.getDoc();
	if (id instanceof CodeMirror.Doc) return findDoc(ts, id);
  }

  function trackChange(ts, doc, change) {
	var data = findDoc(ts, doc);

	var argHints = ts.cachedArgHints;
	if (argHints && argHints.doc == doc && cmpPos(argHints.start, change.to) <= 0)
	  ts.cachedArgHints = null;

	var changed = data.changed;
	if (changed == null)
	  data.changed = changed = {from: change.from.line, to: change.from.line};
	var end = change.from.line + (change.text.length - 1);
	if (change.from.line < changed.to) changed.to = changed.to - (change.to.line - end);
	if (end >= changed.to) changed.to = end + 1;
	if (changed.from > change.from.line) changed.from = change.from.line;

	if (doc.lineCount() > bigDoc && change.to - changed.from > 100) setTimeout(function() {
	  if (data.changed && data.changed.to - data.changed.from > 100) sendDoc(ts, data);
	}, 200);
  }

  function sendDoc(ts, doc) {
	ts.server.request({files: [{type: "full", name: doc.name, text: docValue(ts, doc)}]}, function(error) {
	  if (error) window.console.error(error);
	  else doc.changed = null;
	});
  }

  // Completion

  function hint(ts, cm, c) {
	ts.request(cm, {type: "completions", types: true, docs: true, urls: true}, function(error, data) {
	  if (error) return showError(ts, cm, error);
	  var completions = [], after = "";
	  var from = data.start, to = data.end;
	  if (cm.getRange(Pos(from.line, from.ch - 2), from) == "[\"" &&
		  cm.getRange(to, Pos(to.line, to.ch + 2)) != "\"]")
		after = "\"]";

	  for (var i = 0; i < data.completions.length; ++i) {
		var completion = data.completions[i], className = typeToIcon(completion.type);
		if (data.guess) className += " " + cls + "guess";
		completions.push({text: completion.name + after,
						  displayText: completion.name,
						  className: className,
						  data: completion});
	  }

	  var obj = {from: from, to: to, list: completions};
	  var tooltip = null;
	  CodeMirror.on(obj, "close", function() { remove(tooltip); });
	  CodeMirror.on(obj, "update", function() { remove(tooltip); });
	  CodeMirror.on(obj, "select", function(cur, node) {
		remove(tooltip);
		var content = ts.options.completionTip ? ts.options.completionTip(cur.data) : cur.data.doc;
		if (content) {
		  tooltip = makeTooltip(node.parentNode.getBoundingClientRect().right + window.pageXOffset,
								node.getBoundingClientRect().top + window.pageYOffset, content);
		  tooltip.className += " " + cls + "hint-doc";
		}
	  });
	  c(obj);
	});
  }

  function typeToIcon(type) {
	var suffix;
	if (type == "?") suffix = "unknown";
	else if (type == "number" || type == "string" || type == "bool") suffix = type;
	else if (/^fn\(/.test(type)) suffix = "fn";
	else if (/^\[/.test(type)) suffix = "array";
	else suffix = "object";
	return cls + "completion " + cls + "completion-" + suffix;
  }

  // Type queries

  function showContextInfo(ts, cm, pos, queryName, c) {
	ts.request(cm, queryName, function(error, data) {
	  if (error) return showError(ts, cm, error);
	  if (ts.options.typeTip) {
		var tip = ts.options.typeTip(data);
	  } else {
		var tip = elt("span", null, elt("strong", null, data.type || "not found"));
		if (data.doc)
		  tip.appendChild(document.createTextNode(" — " + data.doc));
		if (data.url) {
		  tip.appendChild(document.createTextNode(" "));
		  var child = tip.appendChild(elt("a", null, "[docs]"));
		  child.href = data.url;
		  child.target = "_blank";
		}
	  }
	  tempTooltip(cm, tip);
	  if (c) c();
	}, pos);
  }

  // Maintaining argument hints

  function updateArgHints(ts, cm) {
	closeArgHints(ts);

	if (cm.somethingSelected()) return;
	var state = cm.getTokenAt(cm.getCursor()).state;
	var inner = CodeMirror.innerMode(cm.getMode(), state);
	if (inner.mode.name != "javascript") return;
	var lex = inner.state.lexical;
	if (lex.info != "call") return;

	var ch, argPos = lex.pos || 0, tabSize = cm.getOption("tabSize");
	for (var line = cm.getCursor().line, e = Math.max(0, line - 9), found = false; line >= e; --line) {
	  var str = cm.getLine(line), extra = 0;
	  for (var pos = 0;;) {
		var tab = str.indexOf("\t", pos);
		if (tab == -1) break;
		extra += tabSize - (tab + extra) % tabSize - 1;
		pos = tab + 1;
	  }
	  ch = lex.column - extra;
	  if (str.charAt(ch) == "(") {found = true; break;}
	}
	if (!found) return;

	var start = Pos(line, ch);
	var cache = ts.cachedArgHints;
	if (cache && cache.doc == cm.getDoc() && cmpPos(start, cache.start) == 0)
	  return showArgHints(ts, cm, argPos);

	ts.request(cm, {type: "type", preferFunction: true, end: start}, function(error, data) {
	  if (error || !data.type || !(/^fn\(/).test(data.type)) return;
	  ts.cachedArgHints = {
		start: pos,
		type: parseFnType(data.type),
		name: data.exprName || data.name || "fn",
		guess: data.guess,
		doc: cm.getDoc()
	  };
	  showArgHints(ts, cm, argPos);
	});
  }

  function showArgHints(ts, cm, pos) {
	closeArgHints(ts);

	var cache = ts.cachedArgHints, tp = cache.type;
	var tip = elt("span", cache.guess ? cls + "fhint-guess" : null,
				  elt("span", cls + "fname", cache.name), "(");
	for (var i = 0; i < tp.args.length; ++i) {
	  if (i) tip.appendChild(document.createTextNode(", "));
	  var arg = tp.args[i];
	  tip.appendChild(elt("span", cls + "farg" + (i == pos ? " " + cls + "farg-current" : ""), arg.name || "?"));
	  if (arg.type != "?") {
		tip.appendChild(document.createTextNode(":\u00a0"));
		tip.appendChild(elt("span", cls + "type", arg.type));
	  }
	}
	tip.appendChild(document.createTextNode(tp.rettype ? ") ->\u00a0" : ")"));
	if (tp.rettype) tip.appendChild(elt("span", cls + "type", tp.rettype));
	var place = cm.cursorCoords(null, "page");
	ts.activeArgHints = makeTooltip(place.right + 1, place.bottom, tip);
  }

  function parseFnType(text) {
	var args = [], pos = 3;

	function skipMatching(upto) {
	  var depth = 0, start = pos;
	  for (;;) {
		var next = text.charAt(pos);
		if (upto.test(next) && !depth) return text.slice(start, pos);
		if (/[{\[\(]/.test(next)) ++depth;
		else if (/[}\]\)]/.test(next)) --depth;
		++pos;
	  }
	}

	// Parse arguments
	if (text.charAt(pos) != ")") for (;;) {
	  var name = text.slice(pos).match(/^([^, \(\[\{]+): /);
	  if (name) {
		pos += name[0].length;
		name = name[1];
	  }
	  args.push({name: name, type: skipMatching(/[\),]/)});
	  if (text.charAt(pos) == ")") break;
	  pos += 2;
	}

	var rettype = text.slice(pos).match(/^\) -> (.*)$/);

	return {args: args, rettype: rettype && rettype[1]};
  }

  // Moving to the definition of something

  function jumpToDef(ts, cm) {
	function inner(varName) {
	  var req = {type: "definition", variable: varName || null};
	  var doc = findDoc(ts, cm.getDoc());
	  ts.server.request(buildRequest(ts, doc, req), function(error, data) {
		if (error) return showError(ts, cm, error);
		if (!data.file && data.url) { window.open(data.url); return; }

		if (data.file) {
		  var localDoc = ts.docs[data.file], found;
		  if (localDoc && (found = findContext(localDoc.doc, data))) {
			ts.jumpStack.push({file: doc.name,
							   start: cm.getCursor("from"),
							   end: cm.getCursor("to")});
			moveTo(ts, doc, localDoc, found.start, found.end);
			return;
		  }
		}
		showError(ts, cm, "Could not find a definition.");
	  });
	}

	if (!atInterestingExpression(cm))
	  dialog(cm, "Jump to variable", function(name) { if (name) inner(name); });
	else
	  inner();
  }

  function jumpBack(ts, cm) {
	var pos = ts.jumpStack.pop(), doc = pos && ts.docs[pos.file];
	if (!doc) return;
	moveTo(ts, findDoc(ts, cm.getDoc()), doc, pos.start, pos.end);
  }

  function moveTo(ts, curDoc, doc, start, end) {
	doc.doc.setSelection(start, end);
	if (curDoc != doc && ts.options.switchToDoc) {
	  closeArgHints(ts);
	  ts.options.switchToDoc(doc.name, doc.doc);
	}
  }

  // The {line,ch} representation of positions makes this rather awkward.
  function findContext(doc, data) {
	var before = data.context.slice(0, data.contextOffset).split("\n");
	var startLine = data.start.line - (before.length - 1);
	var start = Pos(startLine, (before.length == 1 ? data.start.ch : doc.getLine(startLine).length) - before[0].length);

	var text = doc.getLine(startLine).slice(start.ch);
	for (var cur = startLine + 1; cur < doc.lineCount() && text.length < data.context.length; ++cur)
	  text += "\n" + doc.getLine(cur);
	if (text.slice(0, data.context.length) == data.context) return data;

	var cursor = doc.getSearchCursor(data.context, 0, false);
	var nearest, nearestDist = Infinity;
	while (cursor.findNext()) {
	  var from = cursor.from(), dist = Math.abs(from.line - start.line) * 10000;
	  if (!dist) dist = Math.abs(from.ch - start.ch);
	  if (dist < nearestDist) { nearest = from; nearestDist = dist; }
	}
	if (!nearest) return null;

	if (before.length == 1)
	  nearest.ch += before[0].length;
	else
	  nearest = Pos(nearest.line + (before.length - 1), before[before.length - 1].length);
	if (data.start.line == data.end.line)
	  var end = Pos(nearest.line, nearest.ch + (data.end.ch - data.start.ch));
	else
	  var end = Pos(nearest.line + (data.end.line - data.start.line), data.end.ch);
	return {start: nearest, end: end};
  }

  function atInterestingExpression(cm) {
	var pos = cm.getCursor("end"), tok = cm.getTokenAt(pos);
	if (tok.start < pos.ch && (tok.type == "comment" || tok.type == "string")) return false;
	return /[\w)\]]/.test(cm.getLine(pos.line).slice(Math.max(pos.ch - 1, 0), pos.ch + 1));
  }

  // Variable renaming

  function rename(ts, cm) {
	var token = cm.getTokenAt(cm.getCursor());
	if (!/\w/.test(token.string)) return showError(ts, cm, "Not at a variable");
	dialog(cm, "New name for " + token.string, function(newName) {
	  ts.request(cm, {type: "rename", newName: newName, fullDocs: true}, function(error, data) {
		if (error) return showError(ts, cm, error);
		applyChanges(ts, data.changes);
	  });
	});
  }

  function selectName(ts, cm) {
	var name = findDoc(ts, cm.doc).name;
	ts.request(cm, {type: "refs"}, function(error, data) {
	  if (error) return showError(ts, cm, error);
	  var ranges = [], cur = 0;
	  for (var i = 0; i < data.refs.length; i++) {
		var ref = data.refs[i];
		if (ref.file == name) {
		  ranges.push({anchor: ref.start, head: ref.end});
		  if (cmpPos(cur, ref.start) >= 0 && cmpPos(cur, ref.end) <= 0)
			cur = ranges.length - 1;
		}
	  }
	  cm.setSelections(ranges, cur);
	});
  }

  var nextChangeOrig = 0;
  function applyChanges(ts, changes) {
	var perFile = Object.create(null);
	for (var i = 0; i < changes.length; ++i) {
	  var ch = changes[i];
	  (perFile[ch.file] || (perFile[ch.file] = [])).push(ch);
	}
	for (var file in perFile) {
	  var known = ts.docs[file], chs = perFile[file];;
	  if (!known) continue;
	  chs.sort(function(a, b) { return cmpPos(b.start, a.start); });
	  var origin = "*rename" + (++nextChangeOrig);
	  for (var i = 0; i < chs.length; ++i) {
		var ch = chs[i];
		known.doc.replaceRange(ch.text, ch.start, ch.end, origin);
	  }
	}
  }

  // Generic request-building helper

  function buildRequest(ts, doc, query, pos) {
	var files = [], offsetLines = 0, allowFragments = !query.fullDocs;
	if (!allowFragments) delete query.fullDocs;
	if (typeof query == "string") query = {type: query};
	query.lineCharPositions = true;
	if (query.end == null) {
	  query.end = pos || doc.doc.getCursor("end");
	  if (doc.doc.somethingSelected())
		query.start = doc.doc.getCursor("start");
	}
	var startPos = query.start || query.end;

	if (doc.changed) {
	  if (doc.doc.lineCount() > bigDoc && allowFragments !== false &&
		  doc.changed.to - doc.changed.from < 100 &&
		  doc.changed.from <= startPos.line && doc.changed.to > query.end.line) {
		files.push(getFragmentAround(doc, startPos, query.end));
		query.file = "#0";
		var offsetLines = files[0].offsetLines;
		if (query.start != null) query.start = Pos(query.start.line - -offsetLines, query.start.ch);
		query.end = Pos(query.end.line - offsetLines, query.end.ch);
	  } else {
		files.push({type: "full",
					name: doc.name,
					text: docValue(ts, doc)});
		query.file = doc.name;
		doc.changed = null;
	  }
	} else {
	  query.file = doc.name;
	}
	for (var name in ts.docs) {
	  var cur = ts.docs[name];
	  if (cur.changed && cur != doc) {
		files.push({type: "full", name: cur.name, text: docValue(ts, cur)});
		cur.changed = null;
	  }
	}

	return {query: query, files: files};
  }

  function getFragmentAround(data, start, end) {
	var doc = data.doc;
	var minIndent = null, minLine = null, endLine, tabSize = 4;
	for (var p = start.line - 1, min = Math.max(0, p - 50); p >= min; --p) {
	  var line = doc.getLine(p), fn = line.search(/\bfunction\b/);
	  if (fn < 0) continue;
	  var indent = CodeMirror.countColumn(line, null, tabSize);
	  if (minIndent != null && minIndent <= indent) continue;
	  minIndent = indent;
	  minLine = p;
	}
	if (minLine == null) minLine = min;
	var max = Math.min(doc.lastLine(), end.line + 20);
	if (minIndent == null || minIndent == CodeMirror.countColumn(doc.getLine(start.line), null, tabSize))
	  endLine = max;
	else for (endLine = end.line + 1; endLine < max; ++endLine) {
	  var indent = CodeMirror.countColumn(doc.getLine(endLine), null, tabSize);
	  if (indent <= minIndent) break;
	}
	var from = Pos(minLine, 0);

	return {type: "part",
			name: data.name,
			offsetLines: from.line,
			text: doc.getRange(from, Pos(endLine, 0))};
  }

  // Generic utilities

  var cmpPos = CodeMirror.cmpPos;

  function elt(tagname, cls /*, ... elts*/) {
	var e = document.createElement(tagname);
	if (cls) e.className = cls;
	for (var i = 2; i < arguments.length; ++i) {
	  var elt = arguments[i];
	  if (typeof elt == "string") elt = document.createTextNode(elt);
	  e.appendChild(elt);
	}
	return e;
  }

  function dialog(cm, text, f) {
	if (cm.openDialog)
	  cm.openDialog(text + ": <input type=text>", f);
	else
	  f(prompt(text, ""));
  }

  // Tooltips

  function tempTooltip(cm, content) {
	if (cm.state.ternTooltip) remove(cm.state.ternTooltip);
	var where = cm.cursorCoords();
	var tip = cm.state.ternTooltip = makeTooltip(where.right + 1, where.bottom, content);
	function maybeClear() {
	  old = true;
	  if (!mouseOnTip) clear();
	}
	function clear() {
	  cm.state.ternTooltip = null;
	  if (!tip.parentNode) return;
	  cm.off("cursorActivity", clear);
	  cm.off('blur', clear);
	  cm.off('scroll', clear);
	  fadeOut(tip);
	}
	var mouseOnTip = false, old = false;
	CodeMirror.on(tip, "mousemove", function() { mouseOnTip = true; });
	CodeMirror.on(tip, "mouseout", function(e) {
	  if (!CodeMirror.contains(tip, e.relatedTarget || e.toElement)) {
		if (old) clear();
		else mouseOnTip = false;
	  }
	});
	setTimeout(maybeClear, 1700);
	cm.on("cursorActivity", clear);
	cm.on('blur', clear);
	cm.on('scroll', clear);
  }

  function makeTooltip(x, y, content) {
	var node = elt("div", cls + "tooltip", content);
	node.style.left = x + "px";
	node.style.top = y + "px";
	document.body.appendChild(node);
	return node;
  }

  function remove(node) {
	var p = node && node.parentNode;
	if (p) p.removeChild(node);
  }

  function fadeOut(tooltip) {
	tooltip.style.opacity = "0";
	setTimeout(function() { remove(tooltip); }, 1100);
  }

  function showError(ts, cm, msg) {
	if (ts.options.showError)
	  ts.options.showError(cm, msg);
	else
	  tempTooltip(cm, String(msg));
  }

  function closeArgHints(ts) {
	if (ts.activeArgHints) { remove(ts.activeArgHints); ts.activeArgHints = null; }
  }

  function docValue(ts, doc) {
	var val = doc.doc.getValue();
	if (ts.options.fileFilter) val = ts.options.fileFilter(val, doc.name, doc.doc);
	return val;
  }

  // Worker wrapper

  function WorkerServer(ts) {
	var worker = ts.worker = new Worker(ts.options.workerScript);
	worker.postMessage({type: "init",
						defs: ts.options.defs,
						plugins: ts.options.plugins,
						scripts: ts.options.workerDeps});
	var msgId = 0, pending = {};

	function send(data, c) {
	  if (c) {
		data.id = ++msgId;
		pending[msgId] = c;
	  }
	  worker.postMessage(data);
	}
	worker.onmessage = function(e) {
	  var data = e.data;
	  if (data.type == "getFile") {
		getFile(ts, data.name, function(err, text) {
		  send({type: "getFile", err: String(err), text: text, id: data.id});
		});
	  } else if (data.type == "debug") {
		window.console.log(data.message);
	  } else if (data.id && pending[data.id]) {
		pending[data.id](data.err, data.body);
		delete pending[data.id];
	  }
	};
	worker.onerror = function(e) {
	  for (var id in pending) pending[id](e);
	  pending = {};
	};

	this.addFile = function(name, text) { send({type: "add", name: name, text: text}); };
	this.delFile = function(name) { send({type: "del", name: name}); };
	this.request = function(body, c) { send({type: "req", body: body}, c); };
  }
});
